Patent Literature 1 discloses a wireless communications system that wirelessly relays and transmits EDID (Extended Display Identification Data) information according to the HDMI (High-Definition Multimedia Interface).
FIG. 11 is a block diagram showing a configuration of a conventional wireless communications system 1500 disclosed in Patent Literature 1. The wireless communications system 1500 includes a source device 801, a sink device 804, an adaptor device for a source device 802, and an adaptor device for a sink device 803.
First, a control unit 814 in the adaptor device for the sink device 803 reads the EDID information via a wired transmitting and receiving unit 813, a cable C2, a wired transmitting and receiving unit 817, and a control unit 818 from an EDID table 820 that a storage unit 819 has. The control unit 814 stores the read EDID information in an EDID table 816 in a storage unit 815.
Next, the source device 801 wirelessly transmits an authentication requesting signal to the sink device 804 via a cable C1, a wired transmitting and receiving unit 805, a wireless transmitting and receiving unit 806, and an antenna 810. The sink device 804 executes the authentication in response to the authentication requesting signal received via the antenna 811, the wireless transmitting and receiving unit 812, the wired transmitting and receiving unit 813, and the cable C2. Further, the sink device 804 wirelessly transmits an authentication completion signal to the source device 801 via the cable C2 and the adaptor device for the sink device 803.
The source device 801 receives the authentication completion signal via the antenna 810, the wireless transmitting and receiving unit 806, the wired transmitting and receiving unit 805, and the cable C1, and subsequently wirelessly transmits an EDID requesting signal to the sink device 804 via the cable C1 and the adaptor device for the source device 802.
In response to the received EDID requesting signal, the control unit 814 in the adaptor device for the sink device 803 generates an EDID responding signal including in the EDID information stored in the EDID table 816 that the storage unit 815 has, and wirelessly transmits the EDID responding signal to the source device 801.
The control unit 807 in the adaptor device for the source device 802 receives the EDID responding signal via the antenna 810 and the wireless transmitting and receiving unit 806, and stores the EDID information on the sink device 804, which is included in the EDID responding signal, in the EDID table 809 in the storage unit 808.
The source device 801 wirelessly transmits a connection completion notifying signal to the sink device 804 via the cable C1, the wired transmitting and receiving unit 805, the wireless transmitting and receiving unit 806, and the antenna 810.
When the sink device 804 receives the connection completion notifying signal via the adaptor device for the sink device 803 and the cable C2, the sink device 804 wirelessly transmits a connection completion responding signal to the source device 801 via the cable C2 and the adaptor device for the sink device 803.
After the wireless connection processing above is completed, the sink device 804 wirelessly transmits a device designating signal for selecting the source device 801 as the communication destination via the cable C2 and the adaptor device for the sink device 803. The source device 801 receives the device designating signal via the adaptor device for the source device 802 and the cable C1, and wirelessly transmits an ACK signal to the sink device 804 in response to the device designating signal. After that, an AV (Audio Visual) data transmission processing between the sink device 804 and the source device 801 is started via the adaptor device for the source device 802 and the adaptor device for the sink device 803.
As described above, according to the wireless communications system 1500 described in Patent Literature 1, in the sink device 804 and source device 801 including the wired interfaces, the adaptor device for the sink device 803 is attached to the sink device 804, and the adaptor device for the source device 802 is attached to the source device 801. Thereby, the sink device 804 can transmit and receive the EDID information and the video signal through a wireless line.